The present invention relates to a viewfinder device suitable for and positionable in a camera. More particularly, the present invention relates to a viewfinder device to display plural visual field frames by selectively inserting a visual field frame display unit into an optical path of the viewfinder device.
FIG. 6 (PRIOR ART) illustrates a mask member of a prior art viewfinder device of a camera. Three visual field frame display units or portions 52A-52C are positioned in a viewfinder mask member 52. Photographic ranges are defined by three visual field frames 52a-52c positioned in visual field frame display portions 52A-52C. As illustrated in FIG. 6, visual field frame mask member 52 is movable in a left direction M1 and a right direction M2. Movement of mask member 52 in directions M1 and M2 is perpendicular to a viewfinder optical axis (not shown), that extends from mask member 52 to a photographic subject (not shown). By moving mask member 52, visual field frame display portions 52A-52C are positioned in predetermined display positions. As a result, visual field frame display portions 52A-52C are selectively inserted into an optical path of the viewfinder. One of the visual field frames 52a-52c of visual field frame display portions 52A-52C which has been positioned in the display position is then displayed in the viewfinder. A photographic range defined by the displayed visual field frame, 52a, 52b, or 52c, is displayed in a viewfinder image plane, and is presented in a final photographic print.
As illustrated in FIG. 6 (PRIOR ART), visual field frame display portions 52A-52C of the prior art viewfinder are adjacently positioned relative to each other and do not overlap. An amount of space occupied by field frame display portions 52A-52C is necessarily equal to or greater than a sum total of horizontal widths of visual field frame display portions 52A-52C. The size of viewfinder mask member 52 is influenced by the total of the widths of visual field frame display portions 52A-52C. Since the viewfinder mask member 52 has to provide the space required by visual field frame display portions 52A-52C, the viewfinder device is required to be relatively large.